Greg intends to place a 300 square foot pool in his back yard. if the width of the pool is 5 ft shorter then the length, what are the dimensions of the pool?
We have
L (L-5) = 300 simplify
L^2 - 5L= 300
L^2 - 5L - 300 = 0 factor, if possible
(L -20) (L + 15) = 0 so .. setting the factors to 0, we have that L = 20 and L = -15
Reject the -15
So
L = 20
And the width is 5 less = 15